A
angelboyak


thi nghiem ve giao thoa.hai nguon song ket hop s1 s2 cach nhau 10 cm buoc song 2cm .ve vong tron bao ca 2 nguon vao trong.tren vong tron ay co bao nhieu diem dao dongvoi bien do đ cuc dai.
lam on gia chi tiet gium minh voi
dap an 18
lam on gia chi tiet gium minh voi